Condenser

ABSTRACT

The invention relates to a condenser for condensing a vaporous fluid, preferably a condenser designed on the church window principle. The condenser comprises at least one bundle ( 10 ) with a multiplicity of tubes ( 12 ) arranged parallel to one another, the bundle being subdivided into an upper sector ( 16 ) and a lower sector ( 14 ). The tubes have a first fluid flowing through them and the vaporous fluid flowing around them. A condensate discharge element is arranged in the bundle between the upper sector ( 16 ) and the lower sector ( 14 ). The condensate discharge element may be designed as a condensate discharge plane ( 60 ) or else as a condensate discharge duct ( 80 ).

[0001] The invention relates to a condenser, in particular a steamcondenser for use in a steam turbine plant.

[0002] Condensers for condensing a vaporous fluid are employed in manyways in industry. Thus, for example in the chemical industry, condensersfor condensing a wide variety of fluids are often used in conjunctionwith reaction columns.

[0003] However, a very important area of use for condensers is also insteam turbine plants, particularly of power stations. In thelast-mentioned application, as a rule, one or more condensers arearranged in the flow path of the working fluid of the steam turbineprocess at the outlet of the steam turbine or, if a plurality of steamturbines connected in series are used, downstream of the steam turbines.The steam normally comes from an evaporator (boiler of the steam turbineplant) and subsequently at the same time discharging energy, flowsthrough the steam turbine and ultimately into the condenser. In thecondenser, heat is extracted from the steam by heat exchange with acooling fluid, in order to condense the steam again. The condensate issubsequently supplied to the evaporator once again. The cyclic processof the steam turbine plant is thus closed on itself. In addition to thecomponents mentioned, other components (such as, for example, a heatexchanger and, particularly in the case of combined gas and steamturbine plants, additional further heat exchangers) are often arrangedin the flow path of the working fluid.

[0004] Water or water vapor is mostly used as the working fluid in steamturbine plants. As a rule, water is also used for cooling. The inventionis described below in connection with steam turbine plants in whichwater or water vapor is used as the working fluid and water is likewisealso used as the cooling fluid. However, this reference is not intendedto restrict either the general idea of the invention or the use of otherfluids within the meaning of the invention.

[0005] The condenser arranged in a steam turbine plant constitutes avery important component of the steam turbine process and determines thecyclic processing parameters and therefore also the efficiency. Thus,the outlet pressure at the outlet from the steam turbine is set as adirect function of the pressure loss of the fluid (here, for example,steam) when it passes through the condenser. The fluid can thereforealso expand only up to this output pressure in the steam turbine, withthe result that the discharge of energy from the fluid to the turbineand therefore also the efficiency of the turbine are limited. For thisreason, attempts have long been made to provide condensers which bringabout as low a steam-side pressure loss as possible, so that a highermean heat transition coefficient is achieved. However, other parametersmust be taken into account at the same time in the design of acondenser. In particular, the construction volume of a condenser isoften limited. Moreover, in view of the production costs of a condenser,it is also uneconomical, as a rule, to design a condenser with anexcessively large volume, that is to say with long tubes and/or a largenumber of tubes, even though the lower steam flow velocity establishedat the same time would lead to a lower pressure loss. On the other hand,however, in the latter case the pumps feeding the cooling fluid wouldalso have to provide a higher delivery.

[0006] A very important criterion within the framework of a basic designof a condenser is, in particular, also the possibility of using thecondenser for different operating and power output states of a plant(full load, part load) and also use in different plants with differentpower output requirements.

[0007] For these reasons, the concept of the modular makeup of acondenser was developed, which is known in the specialized literature bythe term “Church Window Bundle”. A condenser designed according to thisconcept consists, as a rule, of a plurality of (tube) bundles, eachbundle consisting of a multiplicity of individual tubes. In thiscontext, the exact number and arrangement of the tube bundles weredeveloped with a view to a minimal pressure loss of the inflowing andcondensing steam. The tube bundles can be developed in advance instandardized dimensions. Only the number of necessary bundles of acondenser and the length of the tubes vary, depending on the respectiveapplication and the necessary power output or throughput. The diameterof the tubes may also be varied within particular limits. The individualdesign of a condenser can therefore be carried out extremelycost-effectively and quickly. The basic development and execution ofsuch condensers were described, for example, in Oplatka G., Lang H.,“Theory and Design of Church Window condensers for large steam turbines”Brown Boveri Rev. 60, 1973, but also in patent specification DE 1 948073. One characteristic of such church window bundles is the closedslender tube arrangement and the arrangement of a two-stage air cooler,the latter usually being arranged level with the “waistline” of thecondenser, hence slightly below its geometric center, in so far as thetube bundle is arranged with its greatest extent in the verticaldirection, that is to say so as to stand upright.

[0008] A disadvantage of the previous tube arrangements, however, hasproved to be that the number of tubes is restricted to about 5400 tubesper bundle. If this number is exceeded in an arrangement, an excessiveblockage of the steam paths occurs due to the condensate raining down.This so-called bundle inundation has serious adverse consequences forthe condensation process within the bundles. On the one hand, thesteam-side pressure loss rises considerably. Furthermore, because ofreduced steam penetration, an increased accumulation of air in thebundle occurs. Moreover, due to the thickening of the condensate film onthe outside of the tubes, the heat transmission resistance between thesteam and the cooling fluid is increased considerably. This results in apower loss of the condenser in terms of the parameters relating tocondenser vacuum, oxygen content and condensate subcooling. In addition,the risk of NH₃ corrosion in the case of Cu alloys increases.

[0009] However, bundle sizes of more than 5400 tubes per bundle oftenoccur, for example within the framework of condenser retrofits, in whichthe jacket geometry and water chamber geometry of the condenser arelargely predetermined accordingly.

[0010] The object of the invention is, therefore, to provide a condensermade up from one or more bundles in a modular manner, preferably acondenser designed according to the church window concept, in which thenumber of tubes in a bundle is to be capable of exceeding the previouslimit of about 5400 tubes without a serious loss of power.

[0011] For this purpose, according to the invention, at least one bundleof the condenser has arranged in it a condensate discharge plane whichpreferably forms approximately a right angle with the isobars of thefluid flow flowing around the tubes. The condenser comprises one or morebundles, each bundle, in turn, comprising a multiplicity of tubesarranged parallel to one another and preferably being designed accordingto the church window principle. In this case, the tubes may be arrangedpreferably horizontally, but also vertically or so as to be inclined atan angle. During operation, the tubes have a first fluid flowing throughthem and a vaporous fluid flowing around them, the first fluid used ascooling fluid having, as a rule, a lower temperature than the vaporousfluid. As a result of heat transmission between the first fluid and thevaporous fluid, the steam condenses when it passes through the bundle.At the same time, the condensate precipitates preferably on the tubesand drips or runs downward as a result of the action of gravity. In thepreferred embodiment of the condenser with horizontally arranged tubes,this means that the condensate drips from upper tubes onto tubes locatedbelow them. Where a hitherto conventional bundle is concerned,therefore, in so far as the bundles have a large number of tubesarranged one above the other, it may happen that the lower tubes arecovered completely or virtually completely by a fluid film of thecondensate raining down. The condensate discharge element arrangedbetween the upper sector and the lower sector collects condensatedripping down from the upper sector and discharges this condensate alongthe condensate discharge element. The tubes arranged in the lower sectorbelow the condensate discharge element thus undergo a markedly reducedcondensate load, with the result that the power losses of the condenserare reduced considerably.

[0012] Preferably, the condensate discharge element is arranged in thebundle in such a way that it forms an approximately right angle with theisobaric lines (when condensate discharge elements are not present) ofthe steam flow flowing around the tubes. This ensures that the pressureprofile imparted to the condensate by the steam flow along thecondensate discharge element does not have any discontinuities. If, atthe same time, the condensate discharge element is arranged in such away that the condensate flows off in the direction of the pressuregradient, this additionally assists in transporting the condensate awayby means of the imparted pressure gradient.

[0013] In a preferred embodiment of the invention, the condensatedischarge element is designed as a condensate discharge plane,particularly preferably as a condensate discharge plate. Furthermore, inthe case of horizontally or approximately horizontally arranged tubes ofthe bundle, it is expedient to fasten the condensate discharge plane ineach case to support plates of the bundle. At the same time, thecondensate discharge plane advantageously extends in each case over theentire region between two support plates in each case. The supportplates, usually designed as perforated plates, serve for supporting thetubes of a bundle. As a rule, a plurality of support plates are arrangedin a bundle in each case at a particular distance from one another alongthe tubes. By virtue of the arrangement of a condensate discharge planewhich extends over the entire region between two support plates in eachcase, an upper sector of the tube bundle is delimited completely in thisregion or in these regions by a lower sector of the tube bundle and thecondensate is thus prevented from raining through from the upper sectorinto the lower sector.

[0014] In the case of a layered arrangement of the tubes of a bundle inrows offset to one another, the rows being offset in each case by oneoffset step, it is expedient to arrange the condensate discharge planein the bundle in an arrangement matched to this offset, that is to sayat an offset angle corresponding to the offset step. The condensatedischarge plane thus runs parallel to an offset line and canconsequently be integrated into the bundle, without disturbing theoffset arrangement of the tubes. A nonuniform distribution of the tubesas a result of a disturbed offset arrangement can thus be avoided. Sucha nonuniform distribution of the tubes would lead adversely to anonuniform steam flow (bypass problem) through the tubes and ultimatelyto an increased pressure loss of the steam flow. There is also no needfor a comprehensive redesign and regrouping of the tubes if theinvention is implemented in accordance with the expedient arrangementfor integrating a condensate discharge plane into an already designedtube arrangement or an existing bundle concept. The rows are oftenarranged in each case so as to be offset to one another by an offsetstep corresponding to half the distance between the tube center axes oftwo adjacent tubes of a row.

[0015] In many patterns of arrangement of the tubes, it may be that noneof the offset lines runs approximately perpendicularly to the isobariclines of the steam flow flowing around the tubes. In this case, theoffset line which best achieves the approximately perpendicular run ispreferably employed.

[0016] The condensate discharge plane arranged according to theinvention in the bundle has a first surface and a second surfaceopposite the first surface. In this case, the first surface pointsupward, that is to say condensate dripping down from the upper sectoraccumulates on the first surface. Advantageously, the condensatedischarge plane is arranged in the bundle in such a way that thedistance between the first surface and the tubes facing the firstsurface is greater than the distance between the second surface and thetubes facing the second surface. The ratio of the distances is, in thiscase, preferably two to one. This ensures that there is a sufficientlylarge distance between the first surface and the tubes facing the firstsurface to ensure an undisturbed outflow of the condensate along thecondensate discharge plane.

[0017] It is advantageous, as a rule, to arrange the condensatedischarge element in such a way that the condensate is guided out of theinterior of the bundle onto the outside of the bundle and from hereflows via a so-called main channel of the condenser into a condensatecollecting box. The free condenser space next to the tube bundle isdesignated as the main channel. In some cases, however, it is alsoexpedient, particularly when a void is arranged in the bundle and thisvoid is connected to a main channel or to the condensate collecting box,to supply the condensate to this void by means of the condensatedischarge element.

[0018] In a further preferred embodiment of the invention, a condensatedischarge element designed as a condensate discharge duct is arranged inthe bundle for the purpose of reducing the condensate load on a lowersector of the bundle. The condensate discharge duct has at least onecondensate inlet orifice and at least one condensate outlet orifice.Preferably, the condensate discharge duct is arranged in the bundle insuch a way that condensate which forms inside the bundle is guided outof the bundle by means of the condensate discharge duct. For thispurpose, the condensate enters the condensate discharge duct through thecondensate inlet orifice and is guided in the condensate discharge ductto the condensate outlet orifice. Finally, the condensate passes throughthe condensate outlet orifice preferably into one of the main channelsof the condenser. It is also possible, however, first to supplycondensate to a void arranged in the bundle and to lead it from therefurther on into one of the main channels or into a condensate collectingbox. It is thus possible, by means of a condensate discharge duct, forcondensate which accumulates at the condensate inlet orifice within thebundle to be discharged outward in a controlled way. The condensateraining from above into the sector below the condensate discharge ductis thus reduced by the amount of the discharged fraction. Preferably,the condensate outlet orifice is provided with a tube extension, so thatthe condensate is discharged outward in the form of a jet and isprevented from dripping into or being injected into the tube bundlelocated underneath.

[0019] Preferably, an air cooler box which is arranged above an aircooler of the condenser is designed as a condensate discharge duct. Thetask of an air cooler in a condenser is to cool further the gas/steammixture which is not yet condensed after passage through themultiplicity of tubes of the bundle, in order thereby to achieve ascomplete condensation of the steam as possible. The remainingnoncondensable gas, which has, for example, entered the steam circuitvia seal leakages in the case of a closed steam turbine process, issubsequently vented out of the water circuit of the steam turbineprocess by means of a venting system. Since it is necessary, in anycase, to separate the remaining tubes of the bundle from the air cooler,the installation of an air cooler box on the air cooler can beimplemented in a simple way in terms of construction, even in the caseof already designed condensers, without the arrangement of the tubes ofthe bundle being disturbed as a result. Conventionally, in order toseparate the remaining tubes from the air cooler, a separating plate isprovided on said air cooler, so that the gas/steam mixture can flow intothe air cooler solely through special orifices. By means of an aircooler box arranged according to the invention, the raining ofcondensate down into the sector below the air cooler box is reducedconsiderably, with the result that the effectiveness of the condenser isincreased.

[0020] The invention is explained in more detail below with reference toexemplary embodiments in conjunction with the drawings, in which:

[0021]FIG. 1a shows the inflow of steam to a condenser bundle which isdesigned according to the church window concept;

[0022]FIG. 1b shows the isobaric profile in a condenser bundle accordingto the church window concept;

[0023]FIG. 1c shows a diagrammatic illustration of a condenser made upfrom a plurality of individual bundles;

[0024]FIG. 2 shows a condenser bundle with condensate discharge planesarranged according to the invention;

[0025]FIG. 3 shows an enlarged detail of the condenser bundle from FIG.2;

[0026]FIG. 4 shows a detail of a condenser bundle with condensatedischarge ducts arranged according to the invention;

[0027]FIG. 5 shows an arrangement of two condenser bundles designedaccording to the invention, in each case with two-sided drainageorifices of the condensate discharge ducts;

[0028]FIG. 6 shows a further arrangement of two condenser bundlesdesigned according to the invention, in each case with one-sideddrainage orifices of the condensate discharge ducts.

[0029] Only the elements essential for understanding the invention areshown. Identically acting or similar components are given the samereference symbols in the various illustrations.

[0030]FIG. 1a illustrates a front view of a condenser bundle 10 which isknown from the prior art and has been designed on the church windowprinciple. The characteristic of a bundle designed on the church windowprinciple is a slender tube arrangement with a height of the bundleabout four times its maximum width. The bundle 10 illustrated in FIG. 1acomprises a multiplicity of horizontally arranged tubes which in eachcase run parallel to one another. The tubes are at the same time in eachcase arranged next to one another and one above the other in rows offsetto one another. As a result of the offset arrangement of the tubes, thesteam to be condensed, when passing through the bundle, in each case hasto avoid the tubes of the next row. This results in a largely uniformdistribution of the steam flow in the bundle. FIG. 1a does notillustrate the individual tubes, but merely the arrangement diagram forthe sake of clarity. The intersection points of the arrangement linesreproduce the positions of the tubes. The arrangement diagram in theform of a matrix structure is, as a rule, predetermined by supportplates which are produced in a simple way as perforated plates with anumber of orifices corresponding to the number of tubes and are in eachcase arranged at particular distances from one another along thelongitudinal extent of the bundle. The tubes are in each case insertedthrough the orifices made in the support plates and are supported by thesupport plates. The arrangement of the support plates is not illustratedin FIG. 1a.

[0031] The two-stage air cooler 20 illustrated in FIG. 1a represents afurther typical characteristic of a church window bundle. The air cooleris arranged approximately level with the waistline of the bundle 10,that is to say slightly below the geometric center of the bundle 10, andsubdivides the bundle into a lower part region 14 and an upper partregion 16. The air cooler 20 illustrated in FIG. 1a is designedmirror-symmetrically with respect to the center plane of the bundle. Itwould also be possible, here, to speak of two air coolers arrangedmirror-symmetrically to one another. Since the tubes of the bundleillustrated in FIG. 1a have likewise been arranged mirror-symmetricallywith respect to the center plane 30 of the bundle, the bundle can thusbe subdivided into a left half 32 and a right half 34 mirror-symmetricalto the latter. In the version illustrated here, both halves of the aircooler 20 each have a two-stage makeup, and in each case they comprise afirst region 22, in which the gas/steam mixture entering the air cooleris cooled further, and a second region 24, in which the noncondensablegas is collected and finally vented. The venting device is notillustrated in FIG. 1a. The regions of the air cooler are separated fromthe remaining tubes of the bundle by means of an air cooler casing or bymeans of separating plates, in order to prevent steam from flowingdirectly into the air cooler. Steam can flow into the air cooler 20solely via orifices in the air cooler casing which are made toward thevoid 40 arranged in the middle of the bundle. The void 40 arranged inthe middle of the bundle symmetrically to the center plane of the bundleextends over about half the height of the bundle 10. This free void 40,which is not equipped with tubes and which is also designated as a steamchannel, often serves, in a bundle designed on the church windowprinciple, to ensure an approximately equal pressure loss of the steamflow, irrespective of the inflow into the bundle. Thus, along its flowpath as far as the air cooler, the steam has to overcome a hydraulicresistance, that is to say flow resistance, which is approximately thesame everywhere, irrespective of where it flows into the bundle. Thisensures that steam does not flow into the bundle preferentially via aflow path, but in a uniformly distributed manner.

[0032] The bundle 10 illustrated in FIG. 1a is charged from above withsteam which comes, for example, from a steam turbine. The steam isdistributed to all sides of the bundle 10 according to the flow vectors50 depicted by way of example in FIG. 1a and also penetrates into thebundle 10 from all sides. An optimum flow through the bundle is therebyachieved, in which the distribution of the steam to the tubes takesplace largely uniformly. Regions of the bundle through which the flowpasses inadequately or not at all can thus be avoided.

[0033] Regions of the bundle through which the flow passes inadequatelywould lead locally to intensified and undesirable subcooling of thecondensate and also to a likewise undesirable accumulation ofnoncondensable gases. Consequently, due to the flow passing through thebundle from all sides, optimum efficiency of the condenser is achieved,at the same time with a minimal construction volume of the bundle.

[0034] A further characteristic of a condenser made up from churchwindow bundles is that, as a result of the flow entering the bundle fromall sides and as a result of the air cooler being arranged level withthe waistline of the condenser, negative subcooling of the condensateoccurs, that is to say the temperature of the condensate is higher thanthe saturation temperature corresponding to the pressure at condenserlevel. The physical cause of this is the different flow velocities ofthe steam on the bottom side of the bundle, as compared with the flowvelocities of the steam on the top side of the bundle, along with thepressure difference of the steam caused thereby on the bottom side ofthe bundle, as compared with the top side of the bundle. Negativesubcooling of the condensate is usually desirable.

[0035] The steam flowing into the bundle condenses as a result of heatbeing extracted by the cooling fluid flowing in the tubes and isprecipitated on the tubes. Water is also usually used as cooling fluid.As a result of the action of gravity, the precipitated condensate firstruns downward on the respective tubes, accumulates there andsubsequently drops onto the tubes in each case arranged underneath.There is therefore a greater occurrence of condensate in the lowerregions of a bundle, with the result that the heat transmission betweenthe tube and the steam flow is also impaired.

[0036] In FIG. 1b, isobars of the steam flow are depicted in the bundledesigned according to FIG. 1a. The concentric arrangement of theunimodal pressure depression lines about the bundle axis upstream of theair cooler 20 can be seen clearly. As a result of the acceleration ofthe steam flow, an additional drop in the pressure of the steam flowtoward the air cooler occurs in the steam channel 40.

[0037]FIG. 1c shows a diagrammatic illustration of the makeup of acondenser, in which six bundles 10 a-10 f designed on the church windowprinciple are arranged. The bundles are charged with steam from above.The condensate collects in a condensate collecting box 42 arranged belowthe condenser. The bundles are arranged in such a way that sufficientspace remains in each case between the bundles to ensure an undisturbedflow of the steam around the individual bundles. The space between twobundles in each case is designated as a steam main channel 44. Themodular makeup of the condenser can be seen clearly in FIG. 1c, since,without any higher outlay in terms of design, the condenser could beextended by further bundles or else reduced. It is therefore easilypossible to match the condenser to special requirements, such as, forexample, a necessary power output.

[0038]FIG. 2 illustrates a condenser bundle 10 which is executedaccording to the invention and has been designed on the church windowprinciple. Condensate discharge elements are arranged according to theinvention in the condenser bundle. The bundle illustrated here has aheight of about 6 m and a width of about 1.5 m. The condensate dischargeelements are designed as condensate discharge planes 60 a-60 d, in thebundle illustrated here two condensate discharge planes 60 a, 60 b beingarranged in the lower part region 14 of the bundle and two furthercondensate discharge planes 60 c, 60 d being arranged in the upper partregion 16 of the bundle. The part regions of the bundle are delimitedfrom one another, here, by a horizontally running void 46 and the aircooler 20 arranged below the void. The invention can be implemented bothwith single-stage and with two-stage air coolers.

[0039] At the same time, the condensate discharge planes 60 a-60 d,which are designed in a simple way essentially as a planar plate, arearranged in the bundle in such a way that they in each case form anapproximately right angle with the isobars of the steam flow. The resultof this is that the condensate outflow along the condensate dischargeplanes is neither accelerated nor slowed down excessively by thepressure profile of the steam flow.

[0040] The condensate discharge planes are expediently fastened in eachcase to two support plates of the bundle. The support plates are notillustrated in FIG. 2. The bundle 10 illustrated in FIG. 2 comprises, inaddition to a multiplicity of tubes (the tubes reproduced by means offilled-up circles in FIG. 2 constituting support tubes of the bundle andthe tubes arranged in the edge region of the bundle each being designedwith double the wall thickness), a (single-stage or two-stage) aircooler 20 which is designed symmetrically to the center plane of thebundle and is arranged approximately level with the waistline of thebundle. Each of the symmetrically designed wings of the air cooler 20comprises, on the one hand, a tube-equipped region 22 and, furthermore,a venting device 24. The regions of the air cooler are separated fromthe remaining tube-equipped sectors of the bundle by means of an aircooler casing or by means of separating plates. The steam or thegas/steam mixture not yet condensed until then during passage throughthe tube-equipped part of the bundle enters the tube-equipped region 22of the air cooler solely via the steam channel 40, which is arranged inthe middle of the bundle and extends over a substantial part of theheight of the bundle, and via orifices made in the air cooler casingtoward the steam channel. The gas/steam mixture is cooled once again inthe tube-equipped region 22 of the air cooler, the steam being condensedout essentially completely and only noncondensable gases remaining. Thenoncondensable gases are vented through orifices in the venting box bymeans of vacuum pumps.

[0041] In order to avoid a complicated reorganisation or regrouping ofthe tubes as a result of the insertion of the condensate dischargeplanes 60 a-60 d, the condensate discharge planes 60 a-60 d have in eachcase been arranged in the bundle 10 so as to match the offsetarrangement of the tubes. The tubes of the bundle illustrated in FIG. 2are in each case arranged in rows layered one above the other, each rowbeing arranged so as to be offset by one offset step to the row lyingbelow it and also to the row arranged above it. The offset corresponds,here, in each case to half the distance between the tube center axes oftwo tubes arranged next to one another in a row.

[0042] The distances of the top sides of the condensate discharge planes60 a-60 d from the tubes facing the top sides are selected larger thanthe distances of the bottom sides of the condensate discharge planesfrom the tubes facing the bottom sides. Preferably, the condensatedischarge planes are arranged in such a way that the distance betweenthe top sides and the respective tubes is twice as large as the distancebetween the bottom sides and the respective tubes. The condensateaccumulates on the top sides of the condensate discharge planes andsubsequently runs off along the condensate discharge planes. The largerdistance selected between the top sides and the tubes ensures thatsufficient space remains to make sure of an undisturbed outflow of thecondensate. By contrast, no condensate accumulates on the bottom sides,so that a smaller distance is sufficient.

[0043] The condensate in each case dripping down from above accumulateson the top sides of the condensate discharge planes 60 a-60 d and, byvirtue of the action of gravity, flows off from here along thecondensate discharge planes 60 a-60 d, as identified in FIG. 2 as theflow vector 54. It is thus possible for the condensate raining down in apart region of the bundle to be discharged in a controlled mannereither, for example, into the steam main channels or into the steamchannel arranged centrally in the bundle. In this case, the steamchannel expediently has a condensate outflow, via which the condensatesupplied to the steam channel is led further on either into the steammain channel or directly into the condensate collecting box. The regionlocated in each case below the condensate discharge plane is thusrelieved of the condensate discharged by the condensate discharge planesand coming in each case from the upper region of the bundle, so that areduction in efficiency due to bundle inundation is avoided in theregion below the condensate discharge plane.

[0044] Furthermore, the condensate discharge planes 60 a-60 dillustrated in FIG. 2 have in each case at their lower ends collectinggrooves 62 a-62 d, with the aid of which the condensate running offalong the condensate discharge planes is first collected and guided to alongitudinal position of the bundle, in order to be discharged bunchedtogether into the steam main channel of the steam channel here. For thispurpose, the collecting grooves preferably have orifices at their ends.

[0045] While, according to the illustration in FIG. 2, the condensatedischarge planes 60 c, 60 d arranged in the upper part region 16 of thebundle symmetrically to the center axis of the bundle, guide thecollected condensate in each case into the steam channel 40 provided inthe middle of the bundle, the condensate is guided into the steam mainchannels by the condensate discharge planes 60 a, 60 b arranged in thelower part region 14 and likewise designed symmetrically to the bundlecenter axis. Such an arrangement of the condensate discharge planes 60a-60 d is expedient in as much as the condensate, after flowing out ofthe collecting grooves, thus in both cases has to cover a fallingdistance which is only relatively short in each case. This largelyavoids the condensate splashing back as a result of impingement on, forexample, the condenser bottom.

[0046]FIG. 3 illustrates, enlarged, a detail A from FIG. 2 in order tomake clear the arrangement of the tubes. The tubes 12 a-12 d are in eachcase positioned at the corners of a parallelogram. The tubes 12 a-12 dillustrated in the detail A come from three different arrangement rows,the rows in each case being arranged so as to be offset to one anotherby an offset step corresponding to half the distance between the tubecenter axes of two adjacent tubes.

[0047]FIG. 4 shows a further bundle 10 designed according to theinvention, only a detail of the bundle being illustrated. The detailreproduces an upper tube-equipped part region 16 of the bundle and alower tube-equipped part region 14 of the bundle, a (single-stage ortwo-stage) air cooler 20 designed symmetrically to the center plane ofthe bundle and a steam channel 40 which is arranged in the middle of thebundle and through which the not yet condensed gas/steam mixture flowsinto the air cooler 20. The mirror-symmetrically designed air cooler 20is made up in a similar way to the air cooler illustrated in FIG. 2,each wing of the air cooler comprising a tube-equipped region 22 and aventing device 24 which is arranged on the outsides and which isconnected in each case to a venting duct and to one or more vacuum pumpsnot illustrated in FIG. 4. The tubes of the tube-equipped regions areillustrated in cross section in each case only at the boundaries of theregions. The remaining tubes, which are located within the tube-equippedregions, are reproduced in FIG. 4 merely diagrammatically by thearrangement matrix.

[0048] According to the invention, the air cooler boxes 80 a, 80 b abovethe air coolers 20 a, 20 b are in each case produced as condensatedischarge ducts, the top sides 82 a, 82 b of the air cooler boxes at thesame time also functioning as condensate discharge planes. The aircooler boxes 80 a, 80 b each have a rectangular, internally hollow crosssection and extend both in width and in length over the entire region ofthe air coolers. Condensate dripping down or raining down from abovefirst accumulates on the top side 82 a, 82 b of the air cooler boxes. Inorder to prevent the condensate from flowing off from the top side bothinto the steam main channels and into the steam channel 40, in each casetwo limiting fins 84 a-84 d are additionally mounted on the top side ofthe air cooler boxes and thus delimit the condensate collecting planerelative to the outside. The air cooler boxes are expediently fastenedin the longitudinal direction to the support plates of the bundle, sothat the condensate collecting planes are delimited in the longitudinaldirection by the support plates. A further, small limiting fin 86 a, 86b is arranged in each case directly in front of the condensate inletorifices 88 a, 88 b of the air cooler boxes 80 a, 80 b. When the levelof the condensate which has accumulated on the top side of an air coolerbox exceeds the height of the small limiting fin 86 a, 86 b, condensateflows through the condensate inlet orifice 88 a, 88 b into therespective air cooler box 80 a, 80 b. Furthermore, each of the aircooler boxes 80 a, 80 b has a condensate outlet orifice 90 a, 90 b, viawhich the condensate which has entered the air cooler box can flow outof the air cooler box again. The condensate outlet orifice is preferablydesigned as a tubular piece. The condensate can thus be dischargedoutward in the form of a jet. This prevents the condensate or a drop ofcondensate from splashing back into the tube arrangement lying below it.

[0049] Moreover, the two air cooler boxes 80 a, 80 b illustrated in FIG.4 are connected to one another across the steam channel 40 by means of atubular element 92. Condensate flowing out of the air cooler box 80 alocated on the right in FIG. 4 thus passes into the left air cooler box80 b via the tubular element 92. Such an arrangement of the tubularelement is expedient particularly when the condensate is to flow out ofthe air cooler box on only one side of the bundle. In the execution ofthe invention according to FIG. 4, the condensate which has accumulatedin the two air cooler boxes flows into the left steam main channelsolely via the condensate outlet orifice 90 b of the left air cooler box80 b, while no condensate outflow takes place on the other side. Thetubular elements preferably have a small diameter, so as not to blockthe steam coming from above.

[0050] An outflow on only one side may be expedient, for example, whentwo bundles are arranged at only a short distance from one another. Inorder to prevent outflowing condensate from re-entering the other bundlein each case, the condensate outflow takes place only on that side ofthe bundle which in each case faces away from the adjacent bundle, asillustrated by way of example in FIG. 6. By contrast, FIG. 5 illustratesan arrangement of two bundles 10, 10′, each with a two-sided outflow.

[0051] The bundles 10, 10′ illustrated in FIGS. 5 and 6 also have, inaddition to the air cooler boxes 80 a, 80 b, 80 a′, 80 b′ designedaccording to the invention, in each case four condensate dischargeplanes 60 a-60 d, 60 a′-60 d′ arranged according to the invention.

[0052] With the aid of the bundles designed according to the invention,the condensate load in the lower regions of a bundle can be reducedconsiderably. As a result, the bundles can be made larger, that is tosay with a much larger number of tubes, as compared with the bundlescapable of being produced hitherto, without an appreciable impairment incondenser efficiency occurring as a result of bundle inundation. Thebundles designed according to the invention thus allow a considerableexpansion of the range of use of condensers having a modular makeup, inparticular condensers designed on the church window principle.

LIST OF REFERENCE SYMBOLS

[0053]2 Condenser

[0054]10,10′,

[0055]10 a-10 f (Condenser) bundle

[0056]12 Position of a tube

[0057]14 Lower part region of the bundle

[0058]16 Upper part region of the bundle

[0059]20 Air cooler

[0060]20 a,20 b Wing of the air cooler

[0061]22 Tube-equipped region of the air cooler

[0062]24 Venting device of the air cooler

[0063]26 Air cooler casing

[0064]30 Center plane of the bundle

[0065]32 Left half of the bundle

[0066]34 Right half of the bundle

[0067]40 Void/steam channel

[0068]42 Condensate collecting box

[0069]44 Steam main channel

[0070]46 Horizontal void

[0071]50 Flow vector of the steam flow

[0072]52 Isobars

[0073]54 Flow vector of the condensate

[0074]60,60 a-60 d,

[0075]60 a′-60 d′ Condensate discharge plane

[0076]62 a-62 d Collecting grooves

[0077]70 Support tube

[0078]80 a,80 b,

[0079]80 a′,80 b′ Air cooler box

[0080]82 a, 82 b′ Top side of the air cooler box

[0081]84 a-84 d Limiting fin

[0082]86 a, 86 b Small limiting fin

[0083]88 a, 88 b Inlet orifice

[0084]90 a, 90 b Outlet orifice

[0085]92 Intermediate element

[0086] d Distance between two tube center axes

1. A condenser (2) for condensing a vaporous fluid, with at least onebundle (10), the bundle comprising a multiplicity of tubes (12) arrangedparallel to one another, the tubes (12) having a first fluid flowingthrough them and the vaporous fluid flowing around them, characterizedin that a condensate discharge element (60, 80) is arranged in thebundle (10), the condensate discharge element forming approximately aright angle with the isobars (52) of the fluid flow flowing around thetubes.
 2. The condenser as claimed in claim 1 , the condensate dischargeelement being a condensate discharge plane, preferably a condensatedischarge plate.
 3. The condenser as claimed in one of the precedingclaims, the tubes (12) being arranged in rows, and the rows beingarranged in a layered arrangement one above the other in each case so asto be offset to one another by one offset step, the offset step beingpreferably equal to half the distance (d) between two tube center axes,and the condensate discharge plane (60) being arranged in the bundleapproximately at an offset angle corresponding to the offset step. 4.The condenser as claimed in one of the preceding claims, the condensatedischarge plane (60) arranged in the bundle having a first surface (66)facing the tubes and a second surface (64) opposite the first surface(66), the condensate accumulating on the first surface (66), and thecondensate discharge plane (60) being arranged in the bundle (10) insuch a way that the distance between the first surface (66) and thetubes facing the first surface is larger than the distance between thesecond surface (64) and the tubes facing the second surface, preferablyin a ratio of two to one.
 5. The condenser as claimed in one of claims 2to 4 , a collecting groove (62 a-62 d) being arranged at a lower end ofthe condensate discharge plane (60).
 6. The condenser as claimed in oneof claims 2 to 5 , the bundle (10) having arranged in it a void (40)which is connected to a region outside the bundle by means of an outflowfor the outflow of condensate, and the condensate discharge plane (60)being arranged in such a way that the condensate is led into this void(40) by means of the condensate discharge plane (60).
 7. The condenseras claimed in one of claims 2 to 6 , the condensate discharge plane (60)being arranged in such a way that the condensate is led out of theinterior of the bundle onto the outside of the bundle.
 8. The condenseras claimed in one of the preceding claims, the void (40) being arrangedin the middle of the bundle (10), and two condensate discharge planes(60 c, 60 d), which extend in each case from an outer side of the bundleto the void (40) and lead the condensate into the void (40), beingarranged in an upper region (16) of the bundle in an arrangementsymmetrical to the center plane (30) of the bundle, and two furthercondensate discharge planes (60 a, 60 b), which extend in each case fromthe void (40) of the bundle to an outer side of the bundle and lead thecondensate onto the respective outer side of the bundle, being arrangedin a lower region (14) of the bundle in an arrangement likewisesymmetrical to the center plane (30) of the bundle.
 9. The condenser asclaimed in one of the preceding claims, a condensate discharge duct (80a, 80 b) being arranged as a condensate discharge element in the bundle(10), and the condensate discharge duct (80 a, 80 b) having at least onecondensate inlet orifice (88 a, 88 b) and at least one condensate outletorifice (90 a, 90 b).
 10. The condenser as claimed in claim 9 , an aircooler (20) being arranged in the bundle (10), preferably level with thewaistline of the bundle, and the condensate discharge duct (80 a, 80 b)being arranged on the air cooler (20).
 11. The condenser as claimed inone of claims 9 or 10, the condensate discharge duct (80 a, 80 b)extending from an outer side of the bundle to a void (40) arranged inthe bundle.
 12. The condenser as claimed in claim 11 , the void (40)being arranged in the middle of the bundle, and two condensate dischargeducts (88 a, 88 b) extending in each case from an outer side of thebundle to the void (40) in an arrangement symmetrical to the centerplane (30) of the bundle.
 13. The condenser as claimed in claim 12 , thecondensate discharge ducts (88 a, 88 b) being connected to one anotherby means of an intermediate element (92) which extends over the regionof the void (40).
 14. The condenser as claimed in one of claims 9 to 13, the top side (82 a, 82 b) of the condensate discharge duct (80 a, 80b) being designed as a condensate discharge plane.
 15. The condenser asclaimed in one of the preceding claims, the bundle (10) being a bundledesigned on the church window principle.
 16. The condenser as claimed inone of the preceding claims, the bundle (10) having a height about fourtimes its maximum width, and preferably a two-part air cooler (20) beingarranged in the bundle (10), preferably in a symmetrical arrangement,level with the waistline of the bundle.
 17. The condenser as claimed inone of the preceding claims, steam flowing into the bundle (10) from allsides, and the steam which flows into the bundle from all sides havingto overcome approximately the same flow resistance between the outsideof the bundle and the air cooler.